使用Java建立单向链表

链表（List）是一种经常使用的一种基本数据结构。基本原理如下图片所示$^{[1]}$[1]：

以下使用Java代码实现了包括添加、删除和插入在内的基本操作。

/**
 * 自定义整型链表，包括了添加、删除和插入等操作。
 * @author Wei HAO
 * Date: 2019/04/15
 *
 */
public class IntegerList {

	public static void main(String[] args) {
		IntegerList ln1 = new IntegerList(1);
		ln1.addLast(5);
		ln1.addLast(4);
		ln1.insert(1, 10);
 		ln1.delete(2); 
		IntegerList.print(ln1);
	}

	public int data; // the main content of the node
	public IntegerList next; // the pointer to the next node
	public IntegerList last; // the last node of the current list.
	
	/**
	 * Inserts an element into the specified position.
	 * @param position 
	 * @param data
	 */
	public void insert(int position, int data) {
		IntegerList p = this;
		for(int i = 0; i < position - 1; i++)
			p = p.next;
		
		IntegerList ln = new IntegerList(data);
		ln.next = p.next;
		p.next = ln;
		
		if(p == last)
			last = ln;
	}

	/**
	 * Append a new node with given data to the tail of the list.
	 * @param data The data of a list node.
	 */
	public void addLast(int data) {
		last = last.add(data);
	}

	/**
	 * add a new node to the current node with the given data.
	 * @param data
	 * @return
	 */
	private IntegerList add(int data) {
		IntegerList ln = new IntegerList(data);
		this.next = ln;
		last = ln;
		return ln;
	}

	/** 
	 * Deletes the element at position.
	 * @param position
	 * @return
	 */
	public int delete(int position) {
		IntegerList p = this;
		for(int i = 0; i < position - 1; i++)
			p = p.next;
		int value  = p.next.data;
		p.next = p.next.next;
		return value;
	}
	

	/**
	 * A constructor with no argument.
	 */
	public IntegerList() {
		last = this;
	}

	/**
	 * A constructor with one argument of integer.
	 * @param data The main content of the node.
	 */
	public IntegerList(int data) {
		this.data = data;
		last = this;
	}
	
	
	/**
	 * Print all the data of all the nodes of the list.
	 * @param ln
	 */
	public static void print(IntegerList ln) {
		IntegerList p = ln;
		do {
			System.out.print(p.data + " ");
			p = p.next;
		} while (p != null);
	}
	
	/**
	 * Returns the number of nodes of the current list.
	 * @return
	 */
	public int size() {
		IntegerList p = this;
		int size = 0;
		do {
			size ++;
			p = p.next;
		} while (p != null);		
		return size;
	}
}

[1] 链表图片，百度百科，https://baike.baidu.com/item/链表/9794473?fr=aladdin